thrillwiki_django_no_react/memory-bank/decisions/pghistory-integration.md

Decision: Universal Model History via django-pghistory

Pattern Implementation

• Tracking Method: pghistory.Snapshot() applied to all concrete models
• Inheritance Strategy: Base model class with history tracking
• Context Capture:

  # core/models.py
  import pghistory
  
  class HistoricalModel(models.Model):
      class Meta:
          abstract = True
  
      @pghistory.track(pghistory.Snapshot())
      def save(self, *args, **kwargs):
          return super().save(*args, **kwargs)
  

Integration Scope

1. Model Layer:

   • All concrete models inherit from HistoricalModel
   • Automatic event labeling:

     @pghistory.track(
         pghistory.Snapshot('model.create'),
         pghistory.AfterInsert('model.update'),
         pghistory.BeforeDelete('model.delete')
     )
     

2. Context Middleware:

   # core/middleware.py
   pghistory.context(lambda request: {
       'user': str(request.user) if request.user.is_authenticated else None,
       'ip': request.META.get('REMOTE_ADDR'),
       'user_agent': request.META.get('HTTP_USER_AGENT'),
       'session_key': request.session.session_key
   })
   

3. Admin Integration:

   • Custom history view for Django Admin
   • Version comparison interface